obama sat down with barbara walters. in this moment from their wide-ranging conversation, the first couple is revealing intimate moments from the campaign trail. >> mr. president, mrs. obama, there's a photograph of that you went viral. became the most-shared photograph in the history of twitter. here it is. when you look at this picture, what do you think? at what point was that? >> i think we were campaigning in iowa. >> why were you hugging her so hard in iowa? >> because i love my wife. >> also, i hadn't seen him in a while. when you're campaigning, we're two ships passing in the night. and the first time i saw him was when i walked onstage to greet him. and that's my honey giving me a hug. >> i like giving you hugs. >> how do you keep the fire going? >> that's a good question. >> you know, we've been married now 20 years. >> uh-huh. >> and like every marriage, i think you have your ups and you have your downs. but if you work through the tough times, the respect and love that you feel deepest. -- deepens. >> and the